The image library copies EXIF through resize and orientation baking, and
the JPEG/PNG encoders write it back out. Re-encoding alone therefore did
not remove metadata: sent photos and their thumbnails could carry GPS
coordinates, the camera model and the capture time.
- Clear EXIF and text chunks on both the full image and the thumbnail
right before encoding.
- Treat decoder exceptions on malformed data like an undecodable image.
- Add canStripMetadata() so the UI can warn before a format the library
cannot read (HEIC, RAW) goes out as an untouched document.
Julius Joska